Quite a lot going on in the Arctic Today…
On March 15, 2013, Arctic sea ice extent appears to have reached its annual maximum extent, marking the beginning of the sea ice melt season. This year’s maximum extent was the sixth lowest in the satellite record. NSIDC will release a detailed analysis of the 2012 to 2013 winter sea ice conditions in early April.
So here we are, 9 days into the melt season. Par for the course, we have sea ice melt continuing in most key measures today. Here is a visual of the sea ice extent data from NSIDC:
As you can see, NSIDC extent measures take a rapid dive right to the edge of the -2 standard deviation line. This is a pretty steep decline rate so early in the year and we’d expect it to pause now and then. With current major ice sheet fracturing and storms churning up the ice edges in the Barents and Sea of Okhotsk, these measures will bear close watching.
Fracturing and Rapid Ice Motion
Speaking of fracturing, it is certainly worth taking another look at the very splintered mass of thick ice north of Greenland, the CAA, and Alaska. The most recent satellite shot from the Canadian Weather Office is almost tragic in its poetry. A view down through the clouds provides some stark contrast for all those cracks and leads that have opened up over the past month:
This image provides a static shot of an Arctic in rapid transition. The cracks you can clearly see, however, provide a hint to how volatile even the early spring Arctic has become. What the US Navy CICE map shows (analysis provided by A4R) is that a broad section of thick, multi-year ice is now on the move. It is possible that this new motion will further crack an already fractured system, creating even more leads and melt avenues for spring and summer warming. The CICE motion forecast is below. Again, something that bears close watching:
Lots of features in this Navy ice motion model worth discussing. The first is the motion of thick ice moving away from Greenland and the Canadian Arctic Archipelago (CAA). This is the motion I mentioned above which may result in further fracturing of the thick ice. Other features show rapid movement of ice out the Fram Straight. Fram is, essentially, the graveyard of sea ice, so rapid transport out the Fram is not good for overall ice health. Moving further south, we can see a pretty rapid east-to-west flow in Hudson bay. At this time of year, Hudson is still ice clogged. But we might end up with thinner ice on the east end as a result.
Next come the low pressure systems. The first, rather weak, system appears just north of western Canada and eastern Alaska. This system seems to be combining with a high pressure near Greenland to lift thick ice away from Greenland and the CAA. The second appears in the Bering Sea and appears to be doing a decent job mixing the thin ice there. Finally, a strong low in the Sea of Okhotsk is turning thin ice in that region into a big blender.
Slight Cooling Continues, Temps Still a Bit Above Average
A gradual cooling trend that began a few days ago appears to have bottomed out today. That said, temps still remain mostly above average throughout the Arctic. Taking a look at the global temperature composite provided by NOAA shows much of the warmth concentrated over Greenland, Baffin Bay, and the CAA with other pools of warm air concentrating over the East Siberian, Laptev and Barents Seas.
Overall, conditions still appear to favor slow, overall melting with erosion of sea ice in the Bering and Okhotsk Seas somewhat offset by ice attempting to expand east of Svalbard. Rapid ice transport out the Fram Straight and thick ice lifting away from Greenland and the CAA may create further weaknesses in the ice that could have greater impacts later in the season. We should have a better view of any possible impacts come tomorrow.